Connector for electrodes



Feb. 14, 1950 n. E. STEARNS CONNECTOR FOR ELECTRODES Filed Sept. 50, 1948 D/CA E. 5 fear/75 IN V EN TOR.

' A r roe/v5 m Patented Feb. 14, 1950 UNITED. STATES PATENT", OFFICIE'v 4 Claims.

This invention relatestoconnectorsiorelec trodes such as are used'in-insulation testing devicesand particularly those shown in my Letters Patent No. 2,332,182 and my co-pending application Serial No. 735,259.

Electrodes of this type are particularly useful in testing the insulating coating on amember of substantialy circular cross section such as, for example, a pipeline. Such pipe lines are or dinarily made of iron or steel coated with an insulating coating 1 to protect the metal from deterioration due to electrolysis or the like when such pipes are embeddedin the ground or during exposure to the weather while resting on the ground. Such an insulating coating, to be completely eiiective, must be free from cracks, breakages, flaws, or similardefects known as holidays, as it has been found that a slight defect in suchv insulating coating is actually more harmful than if there were no coating on the pipe, because more current flows through the defective' part per unit of area than would" flow through any part of the pipe per unit of area if it had no coating. ,In other words, the corrosive effect of electrolysis is greatly increased at the locality of any break in the enamel coat- In my above-mentioned patent and cc-pending application, I have described and claimed electrical means for testing an insulating coating of the nature referred to, and. the present application relates more particularly to the means for connecting together the ends of the electrode used in such testing means whenthe electrode is brought into substantially circular conformationx One object of this invention is to provide a swivel connection between the'ends of a sub-" stantially circular electrode, whereby such electrode may freely roll upon a pipe or the like during testing operations without kinking or tightening in a portion only of its coil because of obstructions or uneven surfaces encountered.

Another object of this invention is to provide an electrode formed of a series of coils of resilient material; the ends of which maybe joined together or to the co-acting ends of an electrode, by means permitting relative movements of any portion of the electrode to adapt itself to passage over surfaces of varying degrees of roughness, size or the like.

A further object of this invention is to provide a swivel connection for electrodes or the like wherein a substantially dumbbell 'sha'ped connect ing link'is arranged between" connectors "carried by adjacent portionsof the electrode or thelike', whereby either connectoris free to turnuponor move slightly longitudinally along such link -to v relieve strains.

scription taken in connection with the accom panying drawings illustrating a presently preferred embodiment, andwherein similar reference numerals designate similar parts throughout the several views.

In the drawings:

Fig. 1 is a cross-section through an insulated pipe surrounded by my improved electrode in position for rolling the electrode;

position for rolling movements along such pipe,- witha portion of a testing machineshown-in Fig. 2 is an enlarged longitudinal section throughthe ends of the electrode, showing the---- .s'wivel connection for joining-such electrode ends ;f

and

Fig-3 is a vertical section taken substantially} on the line 3-3 of Fig.2, looking in the direction of the arrows.

- Referring now to the drawings, the-numeral I ll designates a pipe, such as is commonly used-in ly great distances.

earth or other destructive influences, and tests preferably are made to 1 discover any cracks; breakages, flawsor other defects in such coatirig;;- l as the pipe lineis laid, to insure the maintenance of a pipe line of sufiicient-strength to withstand I the' pressures carried therein. An-- electrode l 2 forming a part of a testing apparatus for lo--- eating defectsin the coating H is illustrated as 40'surrounding the coated pipe II] with adjacentportion !3 of such testing apparatus in"posi-- tion for rolling the electrode along the pipe;

Such testing apparatus is described and-claimed in my prior patent and co-pending application above referredto and need not be fully described herein. The electrode I2 is herein shown as com: prising a coiled metallicspringin the opposite ends of which are threaded connectors 14 and 15 The connectors M and I5 are of the same external diameter as the spring and the threads thereon are shaped to conform with the cross section of the metal forming the spring. which in the illustrated embodiment is a respectively (Fig. 2)

substantially square in cross section.

Connector 14 is formed with a front end plate having a rounded or convex front face and substantial thickness. This end plate is provided centrally with an aperture l6 and a socket l'l rearwardly of and of greater diameter than such aperture. Aperture I6 is of suflicient diameter to permit the passage therethrough of the smaller end portion I 8a of a substantially dumbbell-shaped swivel link I 8, the opposite end portion lBb whereof is of greater diameter than the aperture l6 and rounded on its inner face for rolling motion upon the rounded surface of socket [1. Means are provided for retaining the swivel link 18 within connector l4 so that it may not be accidentally displaced or readily detached therefrom, but is free to move therein in substantially any direction. As herein shown, such means-comprises an apertured plate or washer 19 adapted to abut the rear face of the end wall ofco'nnector 'I4 and be held in such abutting position by the resilient split snap ring 20 fitting in a suitable groove 2| in the inner periphery of connector l4.

Connector I is formed with an end plate of lesser thickness than the end plate of connector l4, but which may be reinforced adjacent its central portion, as at l5a. The end plate of this connector also has a rounded convex surface. A central aperture 22 of lesser diameter than either end portion of the swivel link I8 is formed in the end wall of connector I5 and the thickened portion I 5a surrounding the rear portion of the aperture 22 is rounded to form a socket in which the rounded inner face of the smaller end l8a of the swivel link may seat, turn or tilt during the functioning of the electrode. A substantially keyholeshaped slot 23 is formed in the end plate of connector l5 with its larger circular portion adjacent the periphery of the connector and its smaller slot portion leading into the central aperture 22. The larger portion of the keyhole-shaped slot 23 is of sufficient diameter to pass the smaller end We of the swivel link l8, and the smaller slot portion of the keyhole-shaped opening 23 is of suflicient width to permit the passage of only the central neck portion of the swivel link.

In use, the connector I 4 is preliminarily assembled with swivel link [8 in substantially the position shown in Fig. 2, the smaller end 18a of the swivel link having been passed through the central aperture Hi from the rear of the connector and the forward motion of the swivel link continued until the rounded inner surface of the larger end l8b thereof contacts socket 11. Retaining plate l9 and snap ring are then positioned from the rear of the connector to prevent accidental separation of the swivel link l8 from connector M. The connectors l4 and I5 are then secured within the opposite ends of the spring electrode I2, which may be soldered thereto for purposes of anchoring the connectors and insuring an electrical contact between the connector parts and the spring so that the connector parts themselves become a part of the test electrode.

When it is desired to utilize the testing apparatus, the ends of the electrode are brought into proximity with one another after the electrode has been bent around the pipe I 0 to be tested. The smaller end l8a of the swivel link is passed through the circular end of the keyhole-shaped slot 23 from the front of connector l5, and then the central neck portion of the swivel link is moved inwardly through the straight portion of slot 23 into central aperture 22 in the connector [5, where the rounded inner surface of smaller end 18a of the swivel link seats within the socketed rear portion of such central aperture 22.

The tension exerted by spring electrode I2 tends to maintain the end portions of the swivel link It! in constant engagement with the cooperating socket portions of the connectors l4 and I5, but either connector is free to turn upon the swivel link should one end of the electrode be deformed by reason of passage over uneven surfaces or the like, or twisted, as when a portion of the electrode is advanced faster than the remaining portions of the electrode.

The connectors l4 and I5 may give slightly by moving toward each other, or tilt relatively to each other in substantially any direction due to the length of link l8 and the confronting rounded faces of the connectors. In other words, substantially all movements ordinarily encountered in the use of a testing electrode are permitted either connector, without substantial deformation of the electrode and thus provide a substantially continuous annular test electrode surface exposed to the insulating coating under test as the electrode is rolled along the pipe.

The swivel link l8 may either turn with one connector with relation to the other connector or permit both connectors to turn relatively to the swivel link.

To detach the electrode ends, the connectors are moved toward each other until the portion l8a of the swivel link is unseated from its socket,

during which movement member l9 limits rearward movement of link l8 relative to connector l4, whereupon the link l8 may be readily moved radially to enable passage of its smaller end I8a through the large circular portion of slot 23.

While the illustrated embodiment is believed to adequately fulfill the objects and advantages herein stated, it is to be understood that the invention is susceptible to modification and varia tion within the scope of the subjoined claims.

Having described my invention, I claim:

1. Means for swivelly connecting adjacent members comprising a pair of connectors adapted to be secured to said members, one of said connectors having a central aperture and a larger ,interior socket portion coaxial with such aperture,

and the other connector provided with a smaller central aperture and socket rearwardly thereof, a substantially dumbbell-shaped swivel link having rounded end portions of different diameters, the smaller end portion of the swivel link being arranged to pass through the central aperture of the first-mentioned connector and to seat in the socket of the second-mentioned connector, and the larger extremity of the swivel link being arranged to seat in the socket of the first-mentioned connector, said second-mentioned connector being provided with a substantially keyhole-shaped slot leading into its central aperture through which the smaller end of the swivel link may pass to (and from its seat in the socket of said connector.

2. Means for swivelly joining adjacent members comprising a pair of connectors respectively secured in said members, one of said connectors having a central aperture and an interior coaxial socket of larger diameter, a substantially dumbbellshaped swivel link having rounded end portions of different diameters, the smaller end portion of the swivel link being arranged to pass through said aperture in the connector and the larger end portionof the swivel link being adapted to seat in said socket, means for loosely and removably retaining said swivel link within said connector, and the second connector having a central aperture therein of lesser diameter than the 5 smaller end of said swivel link and a socket therebehind for seating the smaller end of the swivel link, said second connector having a slot therein through which the smaller end of said swivel link may be passed to and from seating position within said second connector.

3. Connector means adaptable for use in com junction with a coil spring to join the ends thereof together, to provide a substantially continuous annular contact surface when the spring is rolled along a conduit about which the spring may be fastened, said connector means comprising two connector members having circular peripheries of metal, means carried by each connector member adapted to secure the members respectively to the ends of a spring of the same outer diameter as said circular peripheries and establish connection therebetween, and a link having a universal swivel connection with one of the members and having a readily releasable ball and socket connection with the other member.

4. Connector means for use in conjunction with a coil spring to join the ends thereof together to provide a substantially continuous annular contact surface when the spring is rolled along a conduit about which the spring may be fastened, said connector means comprising two connector members having circular peripheries of metal means carried by each connector member adapted to secure the members to the ends of a spring of the same outer diameter as said circular peripheries and establish contact therebetween, the faces of the connector members which are adapted to confront each other in service having convex contours and a link having a universal swivel connection with one of the members substantially at its axis and having a readily releasable universal swivel connection with the other member substantially at its axis.

DICK E. STEARNS.

REFERENCES CITED UNITED STATES PATENTS Name Date Stearns Oct. 19, 1943 Number 

